refactor: locate project root by pyproject.toml marker

api/schema.py

@@ -33,7 +33,13 @@ def is_wecker_ringing() -> bool:
 
 
 def _project_root() -> Path:
-    return Path(__file__).parent.parent.absolute()
+    """Locate the project root by searching upward for pyproject.toml."""
+    start = Path(__file__).resolve()
+    for parent in start.parents:
+        if (parent / "pyproject.toml").exists():
+            return parent
+    # Fallback for unusual layouts; keep a sensible default.
+    return start.parent.parent
 
 
 def _default_command() -> str: